Air heater



pril 13, 1954 M. H. WINNER, JR 2,675,460

AIR HEATER Filed May 5, 1955 2 Sheets-Sheet l INVENToR.

Mae H. WMM/Ee, Je.

i BY

April 13, 1954 M. H. WINNER, JR

AIR HEATER 2 Sheets-Sheet 2 Filed May 5 1953 INVENTOR. MHRK h- //A/A/EE,Je.

Patented Apr. 13, 1954 UNITED STATES PATENT QFFICE AIR HEATER Mark H.Winner, Jr., New York, N. Y.

Application May 5, 1953, Serial No. 353,189

(Cl. 21S-39) 2 Claims. 1

This invention relates to heating devices, and more particularly hasreference to an air heater of the type wherein air is circulated throughthe device by a blower means, and is electrically heated during itspassage through said device.

Summarized briefly, the present invention includes an upstanding housingof generally ilat outer coniguration, arranged to occupy a minimumspace. Formed within the housing is an air conduit, the opposite ends ofwhich are communicated with the atmosphere exteriorly of the housingthrough inlet and outlet openings formed in the housing. The conduit,according to the present invention, is of spiral formation, the spiralbeing ofthe flat type and lying in a vertical plane. A centrifugalblower mounted in the housing at the inner end of the spiral is arrangedto draw air inwardly through the inlet opening of the housing, and toforce said air longitudinally of the conduit for discharge from theoutlet opening. Within the conduit an elongated resistance element ismounted, said element being spiralled correspondingly to the conduit andextending substantially the full length of the conduit to warm airduring the passage thereof between the inlet and outlet openings.

The extension of the air conduit through a flat, vertically disposedspiral desirably elongates the air passage, while at the same timeconning the passage to a relatively small cubic area. the same time, thespiral formation of the heating element, with said element extendingfrom end to end of the conduit, increases the eiciency with which theair is heated during passage thereof between the inlet and outletopenings of the heater.

The main object of the invention, accordingly, is to provide an airheater wherein the radiant heat of an electrical heating element will beutilized with maximum eiciency to warm air passing through a spirallngduct or conduit, thus to allow the space into which the warmed air isdischarged to be evenly heated by convection, rather than by therelatively uneven heating resulting from heat radiation from a heatingunit of comparable size.

Another object of importance is to provide, in a device of the typestated, a simplified construction that will facilitate the assembling ofthe parts. To this end, I propose to form the heating device with ahousing the back of which will initially be open. Thereafter, a flatsupport plate is mounted in the back of the housing to close the same,and preassembled with said plate is a spirally extended conduit wall,said wall pro- All.

jecting forwardly from the plate, so as to engage against the innersurface of the front wall cf the housing. In this way, the housing,plate, and conduit wall cooperate to define the spiral duct. Thecentrifugal blower, the motor associated therewith, and the heatingelement are all mounted on the support plate, so as to be preassembledwith said support plate along with the conduit wall, prior to insertionof the plate in the open back of the housing.

Another object of importance is to provide a heater of the type statedwhich will be so designed as to permit the same to be used not only as aroom or space heater. but also, with slight modifications, as a hairdryer, drying means to be associated with a washing means, etc.

Other objects will appear from the following description, the claimsappended thereto, and from the annexed drawings, in which like referencecharacters designate like parts through the several views, and wherein:

Figure 1 is a perspective view of a heating device formed in accordancewith the present invention;

Figure 2 is an enlarged sectional view taken substantially on line 2-2of Figure 1;

Figure 3 is a transverse sectional view taken substantially on line 3-3of Figure 2;

Figure 4 is a diagrammatic view showing the electrical circuit embodiedin the invention; and

Figure 5 is an enlarged, detail sectional View taken substantially online 5--5 of Figure 2.

Referring to the drawings in detail, the reference numeral l0 has beenapplied generally to a housing, which housing can be formed from sheetmetal material or the like. The housing, in the illustrated embodimentof the invention, wherein a room heater has been illustrated, includes aflat, horizontally disposed, rectangular bottom wall I2 integral orotherwise made rigid at its opposite ends with relatively short,depending legs I4. Projecting upwardly from the opposite ends of thebottom Wall I2 are side walls I6, said side walls being verticallydisposed and being in tegral with the opposite side edges of a generallysquare, vertically disposed front wall I8.

The back of the housing l0 is formed open, but at its top, the housinghas a horizontally disposed top wall 20.

Preferably, a handle 22 is secured to the top wall 2t, to facilitatemovement of the heater from place to place.

Formed centrally in the front wall I8 is a circular air inlet opening24, and mounted in said opening is a register 26 of barred or open meshformation.

In the top wall 2l), intermediate opposite ends of the top wall, arelatively elongated rectangular opening 28 is formed, said openingcomprising an air outlet opening.

Mountable within the housing I is a conduit and heating assembly 30,which assembly includes a flat support plate 32. The support plate 32 isof rectangular outer configuration, the periphery of said plate fittingsnugly within the open back of the housing, thus to cause the plate toclose the housing at its back when the assembly 30 is mounted within thehousing.

The plate 32, at its center, has an opening 34 through which extends thehorizontally disposed shaft of an electric motor 36 mounted in back ofthe plate 32 upon a bracket 38 of inverted U shape Iixedly secured tothe back surface of the plate 32.

Secured to the forwardly projected portion of the motor shaft is acentrifugal blower 40, said blower 40 being disposed concentrically withthe inlet opening 24, and being so arranged as to draw air inwardlythrough said inlet opening, when the blower is in operation.

Prior to mounting of the plate 32 within the housing, I assemble withsaid plate an elongated strip of sheet metal or the like, said stripbeing designated by the reference numeral 42 and having one edge fixedlyengaged in a spirally extending groove 44 formed in the plate 32.;

The strip 42, when mounted in said groove, denes a conduit wall, saidstrip projecting forwardly from the plate 32 into engagement with thefront wall I 8 of the housing.

At one end, the strip 42 is provided with an ear 43, secured to theplate 32 by means of a screw 43 or an equivalent fastening element.Other ears U, 52, 54, 5B, 58 are spaced longitudinally of the strip 42,and are similarly secured to the plate 32, thus to dispose the strip ina spiral path. A short strip portion 60 is mounted upon the plate 32,adjacent the top edge of said plate, said strip portion 68 being securedto the plate by means of an ear 62, and being so formed as to cooperatewith the outer end of the strip or conduit wall 42 in dening a widenedoutlet for an air duct defined by the strip, plate 32, and front walli8.

It will be seen that on insertion of the plate 32 within the housing,there is provided a relatively elongated air conduit, the inner end ofwhich is in communication with the inlet opening 24, and the outlet endof which is in communication with the outlet opening 28. In thisconnection, the outer end of strip 42 and the outer end of strip portionte are secured to the plate 32 at opposite ends of the opening 23, andspaced longitudinally of opening 28 are transversely disposed louvers34, said louvers 64 being each provided, at one end, with an ear wherebythe louvers are iixedly secured to and project forwardly from the plate32.

Within the air conduit I mount an elongated electrical resistance unit66, said unit 65 being disposed spirally in correspondence with thespiral formation of the conduit, and extending substantially from end toend of said conduit as best shown in Figure 2. The unit 66 is disposedmedially between the opposite side walls of the conduit, and is alsospaced outwardly from the inner wall of the conduit defined by the plate32.

To mount the unit 66 in this position, I provide support posts 68,spaced longitudinally of the heating unit or element, said posts 68being of insulating material and being formed. as shown in Figure 3,with openings in their outer ends through which the unit extends. Theinner ends of the posts 68 are reduced and threaded, and extend throughopenings formed in the plate 32, nuts being threaded upon the reducedportions of said posts 68 to mount the posts upon the support plate.

At one end, the resistance element 66 is provided with a terminal, whichhas been shown to its best advantage in Figure 5. As will be noted. asupport post 10 of insulating material has a reduced, threaded inner endportion or base 12 extending through a smooth walled opening formed inthe plate 32, a nut 14 being threaded upon said base to secure the post10 in position upon the support plate.

Formed in the post 10 is an axial bore. and extending through said boreis a conductive terminal screw 16, to one end of which is connected theadjacent end of the resistance element 66. To the other end of theterminal screw there is connected a lead 18.

The other end of the resistance element 66 is secured to a similarterminal 16, and extending from the last-named terminal is a second lead18.

Referring now to Figure 4, wherein the electrical circuit embodied inthe invention has been shown, it will be noted that the motor 36 isconnected, through the medium of the leads 18, to the element G5, inparallel with said element. In this connection, there is extended fromone of the resistance element terminals a lead 80, said lead 8Uextending from one side of the house circuit. A lead 82 extends from theother resistance element terminal, to the other side of the housecircuit, the leads 80, 82 being encased in the sheath of an electriccord 83 having the usual lug, whereby the device can be connected to anordinary convenience outlet.

A switch 84, adapted to be operated either manually or thermostatically,as desired, is in series with the motor and resistance element, saidswitch being mounted in the lead 82 in the illustrated example of theinvention.

Preferably, the device is designed to minimize heat losses throughradiation, and to this end, the inner surface of the front wall I8 iscovered by sheet insulation 86, which insulation may in turn be aided,in resisting heat losses through radiation, by aluminum paint or thelike.

Similarly, the plate 32 is provided, over its full area, with sheetinsulation 88, and again, aluminum paint may be used to further reduceradiant heat losses.

After the assembly 30 has been mounted in place within the housing l0, aback cover plate is inserted in the back of the housing, said plate 98being spaced rearwardly from the plate 32 as shown in Figure 3. Plate 9Uhas a center opening 82, the motor 36 projecting rearwardly through saidcenter opening. In this way, the motor will be partly disposedexteriorly of the housing, thereby to facilitate cooling of the motor.

It will be noted that any suitable means can be employed to mount theassembly 30 and cover plate 30 in place, and as one example of such ameans, I show connecting bolts 94, one bolt 94 being provided at eachcorner of the housing. The bolts 94 would extend through suitableopenings formed in plates 32, 98, and may be threaded in sockets formedin the corner portions of the front wall i3.

In the illustrated example of the invention, there has been shown aspace heater, which can be used to advantage at any desired locationwithin an enclosure such as a room. It will be observed that when thedevice is in operation, the blower will draw air inwardly through theopening 2li, and will cause said air to travel through a spiral path,from the inner to the outer end of the conduit. At the outer end of theconduit, the air is diffused, passing through the outlet opening 28,thus to eiiciently warm the space surrounding the heater. It isimportant to note, in this regard, that radiant heat losses are cut downto a minimum, thus to cause the heater to warm the space by convection,rather than by radiation. Efhcient use is made of the heating element,by formation of the heating element as a spiral, extending incorrespondence with the spiral duct formation and formed to a lengthgenerally approximating that of said duct.

Further, it is important to note that the heating element is so disposedas to be spaced outwardly from the several walls of the duct, theheating element extending longitudinally and centrallyT of the duct. Inthis way, the radiant heat emanating from the element will warm the ductwalls, thus causing the air passing through the duct to become heated byimpingement thereof upon the walls and element.

I believe it is sufficiently obvious as not to require specialillustration that the device could be used not only as a room heater,but also as a hair dryer, dryer means for a clothes washing machine,etc. Some small modifications might, of course, be necessary in theseinstances, but the basic construction illustrated and described would, Ibelieve, remain unchanged. When used as a hair dryer, the device couldbe iitted with an elongated attachment mountable upon the top wall 20,said attachment extending from the outlet opening 28 to a discharge headthrough which air can be directed against the hair of a user. When thedevice is to be used as a main or supplementary drying means associatedwith a clothes washer, the device could be mounted directly within theouter casing of the washer, with a duct extending from the outletopening Zd to the interior of the washer, where it will Warm clothesduring, for example, a spin-dry cycle.

Apart from the spiral design of the duct and heating element, theconstruction which I have devised has other advantages which are thoughtworthy of note. Among these is the construction wherein the assembly 3dcan be manufactured as a separate unit, with all the parts thereof beingpre-assembled prior to insertion of `said assembly within the housingIii. Since the assembly 3B is secured in the housing only by theconnecting bolts 94, removal of said bolts will permit the entireassembly 3e to be removed bodily, for performance of necessarymaintenance, repair, or cleaning operations.

Further, it is to be noted that at the duct outlet, the duct widenssubstantially. The effect of this arrangement is to decrease blast andextreme temperatures at the outlet, and to provide, instead, an airdistribution that is characterized by its evenness and the comfortablelevel of the air temperature.

It is believed apparent that the invention is not necessarily confinedto the specific use or uses thereof described above, since it may beutilized for any purpose to which it may be suited. Nor is the inventionto be necessarily limited to the specific construction illustrated anddescribed, since such construction is only intended to be illustrativeof the principles of operation and the means presently devised to carryout said principles, it being considered that the invention comprehendsany minor change in construction that may be permitted within the scopeof the appended claims.

What is claimed is:

1. An air heater comprising an upstanding housing generally hat inrespect to the outer configuration thereof and having an open back; ailat support plate mounted in the open back of said housing to close thesame; a spiral conduit carried by said plate and lying in a verticalplane, the housing having an air inlet opening in one of its side Wallscommunicating with the inner end of said conduit and an air outletopening in its top wall communicating with the outer end of saidconduit; a centrifugal blower mounted in the inner end of the conduitand arranged to pull air inwardly through said inlet opening and forcethe same longitudinally of the conduit for discharge from the outletopening; and a heating element spiralled correspondingly to the airconduit and extending longitudinally of the conduit substantially fromend to end thereof, for warming said air during passage thereof throughthe conduit.

2. An air heater comprising an upstanding housing generally fiat inrespect to the outer configuration thereof and formed with an open back,an outlet opening in its top wall, and an inlet opening disposedcentrally in its front wall; a flat support plate removably mounted inthe open back of the housing to close the same; a spira-liv formedconduit wall mounted upon said plate and projecting forwardly therefrominto engagement with the front wall of the housing, said front wall,plate, and conduit Wall cooperating to form, withi the housing, aspirally extending air conduit, said inlet opening communicating withthe inner end 0f said conduit and said outlet opening communicating withthe outer end of the conduit; a centrifugal blower mounted upon saidplate at the inner end of the conduit and arranged to draw air inwardlythrough said inlet opening and force the same longitudinally of theconduit, for discharge of the air through the outlet opening; and aheating element mounted upon said mounting plate and extending spirallywithin the conduit substantially from end to end thereof, for warmingsaid air during the passage thereof through the conduit.

References Cited in the file of this patent UNITED STATES IATENTS NumberName Date '745,507 De Mare Dec. 1, 1903 2,479,571 Hewitt Aug. 23, 1949

